From 3237edc480f0f0491da2aad176b7646dbbe4779f Mon Sep 17 00:00:00 2001
From: Mathieu Westphal <mathieu.westphal@kitware.com>
Date: Sun, 16 Feb 2025 20:12:21 +0100
Subject: [PATCH] OBJImporter: Read mtllib keyword when parsing OBJ
---
IO/Import/vtkOBJImporter.cxx | 136 +++++++++++++++++++++++++----------
1 file changed, 98 insertions(+), 38 deletions(-)
diff --git a/IO/Import/vtkOBJImporter.cxx b/IO/Import/vtkOBJImporter.cxx
index 14d1e6fa81a..5f76c1955d3 100644
--- a/IO/Import/vtkOBJImporter.cxx
+++ b/IO/Import/vtkOBJImporter.cxx
@@ -366,24 +366,113 @@ int vtkOBJPolyDataProcessor::RequestData(vtkInformation* vtkNotUsed(request),
delete this->parsedMTLs[k];
}
- // If the MTLFileName is not set explicitly, we assume *.obj.mtl as the MTL
- // filename
+ // If the MTLFileName is not set explicitly, we look for a mtllib in the obj
+ // if not available we look for .mtl or *.obj.mtl as the MTL filename
std::string mtlname = this->MTLFileName;
+ char *pLine, *pEnd, *cmd;
+ auto _extractLine = [&](char* rawLine)
+ {
+ pLine = rawLine;
+ pEnd = rawLine + strlen(rawLine);
+
+ // watch for BOM
+ if (pEnd - pLine > 3 && pLine[0] == -17 && pLine[1] == -69 && pLine[2] == -65)
+ {
+ pLine += 3;
+ }
+
+ // find the first non-whitespace character
+ while (isspace(*pLine) && pLine < pEnd)
+ {
+ pLine++;
+ }
+
+ // this first non-whitespace is the command
+ cmd = pLine;
+
+ // skip over non-whitespace
+ while (!isspace(*pLine) && pLine < pEnd)
+ {
+ pLine++;
+ }
+
+ // terminate command
+ if (pLine < pEnd)
+ {
+ *pLine = '\0';
+ pLine++;
+ }
+ };
+
if (this->DefaultMTLFileName)
{
- mtlname = this->FileName + ".mtl";
- if (vtksys::SystemTools::FileExists(mtlname))
+ bool mtllibDefined = false;
+ { // (make a local scope section to emphasise that the variables below are only used here)
+
+ const int MAX_LINE = 100000;
+ char rawLine[MAX_LINE];
+
+ while (fgets(rawLine, MAX_LINE, in) != nullptr)
+ {
+ _extractLine(rawLine);
+
+ // in the OBJ format the first characters determine how to interpret the line:
+ // Skip comments
+ if (strcmp(cmd, "#") == 0)
+ {
+ continue;
+ }
+ // mtllib is the first non-commmented line
+ else if (strcmp(cmd, "mtllib") == 0)
+ {
+ while (isspace(*pLine) && pLine < pEnd)
+ {
+ pLine++;
+ }
+ // Recover the mtllib without the \n at the end
+ mtlname = vtksys::SystemTools::GetFilenamePath(this->FileName) + "/" +
+ std::string(pLine, strlen(pLine) - 1);
+ mtllibDefined = true;
+ break;
+ }
+ // no mtllib in this file, just break;
+ else
+ {
+ break;
+ }
+ }
+ // Reset file position
+ rewind(in);
+ }
+
+ if (mtllibDefined)
{
- this->MTLFileName = mtlname;
+ if (vtksys::SystemTools::FileExists(mtlname))
+ {
+ this->MTLFileName = mtlname;
+ }
+ else
+ {
+ vtkErrorMacro(<< "The MTL file set by the mtllib command " << mtlname
+ << " could not be found");
+ }
}
else
{
- mtlname = vtksys::SystemTools::GetFilenamePath(this->FileName) + "/" +
- vtksys::SystemTools::GetFilenameWithoutLastExtension(this->FileName) + ".mtl";
+ mtlname = this->FileName + ".mtl";
if (vtksys::SystemTools::FileExists(mtlname))
{
this->MTLFileName = mtlname;
}
+ else
+ {
+ mtlname = vtksys::SystemTools::GetFilenamePath(this->FileName) + "/" +
+ vtksys::SystemTools::GetFilenameWithoutLastExtension(this->FileName) + ".mtl";
+ if (vtksys::SystemTools::FileExists(mtlname))
+ {
+ this->MTLFileName = mtlname;
+ }
+ }
}
}
else
@@ -395,7 +484,7 @@ int vtkOBJPolyDataProcessor::RequestData(vtkInformation* vtkNotUsed(request),
}
int mtlParseResult;
- this->parsedMTLs = ParseOBJandMTL(MTLFileName, mtlParseResult);
+ this->parsedMTLs = ParseOBJandMTL(this->MTLFileName, mtlParseResult);
if (this->parsedMTLs.empty())
{ // construct a default material to define the single polydata's actor.
this->parsedMTLs.push_back(new vtkOBJImportedMaterial);
@@ -463,36 +552,7 @@ int vtkOBJPolyDataProcessor::RequestData(vtkInformation* vtkNotUsed(request),
while (everything_ok && fgets(rawLine, MAX_LINE, in) != nullptr)
{ /** While OK and there is another line in the file */
lineNr++;
- char* pLine = rawLine;
- char* pEnd = rawLine + strlen(rawLine);
-
- // watch for BOM
- if (pEnd - pLine > 3 && pLine[0] == -17 && pLine[1] == -69 && pLine[2] == -65)
- {
- pLine += 3;
- }
-
- // find the first non-whitespace character
- while (isspace(*pLine) && pLine < pEnd)
- {
- pLine++;
- }
-
- // this first non-whitespace is the command
- const char* cmd = pLine;
-
- // skip over non-whitespace
- while (!isspace(*pLine) && pLine < pEnd)
- {
- pLine++;
- }
-
- // terminate command
- if (pLine < pEnd)
- {
- *pLine = '\0';
- pLine++;
- }
+ _extractLine(rawLine);
// in the OBJ format the first characters determine how to interpret the line:
static long lastVertexIndex = 0;
--
GitLab